Tetrasaccharide Resin Glycosides with Nitric Oxide Production Inhibitory Activity from Cuscuta campestris

LC-HRMS/MS-based molecular-network-guided chemical investigation of Cuscuta campestris led to the isolation of seven undescribed tetrasaccharide-type resin glycosides (1-7). Their structures were elucidated using 1D and 2D NMR and HRESIMS analysis. Isolated resin glycosides were comprised of d-glucose, d-fucose, d-quinovose, and l-rhamnose, and these monosaccharides were partially acylated with acetyl, isobutyryl, n-hexanoyl, and niloyl organic acids. The absolute configuration of aglycones were determined as S-configuration using Mosher's method after acid hydrolysis of resin glycoside fraction. All compounds were evaluated for their inhibitory activity against the production of nitric oxide in RAW 264.7 cells. Compounds 2 and 3 exhibited inhibitory activity, with IC₅₀ values of 14.3 and 10.4 μM, respectively.